I am in life sciences! While you can find some examples of things becoming outdated you don’t need entire new textbooks. Addenda/errata can be appended to the document. Or the instructor can point out the error and teach the new “truth”
You’re right; smaller-scale changes can be captured in errata.
However, some things move pretty quick and warrant updates to the whole document especially when the document is used a handbook in critical situations. The ACLS protocol manual, updated quinquennially, comes to mind.
Some textbook publishers are intentionally making small changes from year to year to intentionally make the life of those using second hand text books miserable.
Corporations have long since realised that often their biggest competition comes from their own products therefore we now have planned obsolescence (someone who already has your product and doesn't want to buy another) and the war on secondary markets (someone other than you selling your, old, product).
